The manufacture and packaging of electronic components or workpieces such as semiconductors and flat panel displays often takes place within a series of individual processing stations that are designed to perform a specific type of processing operation such as a deposition, an etching, a thermal processing, or a cleaning. Processing systems have been designed in which multiple processing stations are arranged sequentially to form an in-line tool or are positioned in a cluster to form a cluster tool. Plasma treatment chambers are incorporated into processing stations for exposing workpieces to a plasma in preparation for another operation in a successive processing station. A plasma treatment process is used to etch, clean or otherwise process or treat a surface of the workpiece. Workpieces are often transferred to and from the plasma treatment chamber via a conveyor, robot or manually; and other workpiece handling devices are used to shuttle the workpieces into and out of a plasma treatment chamber.
While such plasma treatment systems have worked reasonably well in the past, the structure of such systems imposes certain limitations on their operation that limit system efficiency and throughput. For example, most processing systems are in-line serial processing systems that utilize in-line parts conveyors. Therefore, one treatment chamber normally treats only one individually-handled workpiece at a time. In some applications, it is possible to simultaneously process two individually-handled workpieces in the plasma chamber; however, it is believed that two is the maximum number of individually-handled workpieces that have been simultaneously processed in known plasma treatment chambers.
Another limitation in the structure of conventional plasma treatment systems relates to the workpiece handling systems that are currently available. Known workpiece handling systems are relatively bulky and large and make the handling of workpieces, either individually or in bulk, within a small volume extremely difficult.
Another disadvantage of known plasma treatment systems is that a plasma treatment machine has a fixed footprint that consumes a fixed amount of manufacturing floor space. Thus, every time another plasma treatment machine is added to increase throughput, additional manufacturing floor space is required in direct proportion to the number of plasma machines added. The cost of additional floor space is substantial and may require the construction of an additional structure or building. Another disadvantage arising from processing a single workpiece at a time in a plasma treatment chamber is a less efficient use of electric and gas utilities.
Therefore, there is a need to substantially improve processing efficiency of the plasma treatment system. There is a further need to improve the throughput of each plasma treatment machine footprint. There is a still further need to provide material handling devices that are more compact and have the ability to handle workpieces, both in bulk and individually, more quickly and efficiently.